Stickiness Values Research Articles

Influence Of Trehalose Addition On Instrumental Textural Properties Of Strawberry Pastes

Objective of this study was investigation of influence of trehalose addition (3, 5 and 10%) on instrumental textural properties of evaporated and freeze-dried strawberry pastes. As a control, strawberry paste without addition of trehalose was used. Addition of trehalose had influence on both, hardness and stickiness of the samples, but it is very important to define the amount of trehalose in order to achieve desirable properties. With addition of trehalose hardness of both, evaporated and freeze-dried samples decreased, from 29.89 N to 14.72 N for evaporated samples and from 184.83 N to 44.95 N in freeze-dried samples. Also, from those results it could be seen that freeze-dried samples were much harder than evaporated ones, regardless of trehalose addition. While hardness of samples decreased with addition of trehalose, stickiness increased. Stickiness values were from 0.016 N to 0.0102 N for evaporated samples, and from 0.066 N to 0.018 N for freeze-dried samples. Since evaporated samples had lower values for stickiness they were stickier than freeze-dried ones.

Effect of carboxymethylcellulose and pregelatinized corn starch on the quality of amaranthus spaghetti

Six gluten-free spaghetti typologies in base of amaranthus flour were produced, using two types of gluten substitutes, carboxymethylcellulose sodium salt (CMC) at three different percentages, 0.1% (LCMC), 0.2% (MCMC), 0.3% (HCMC) and pregelatinized corn starch (PCS) at three different percentages, 5% (LPCS), 7% (MPCS), 9% (HPCS). The amaranthus spaghetti were compared with a control spaghetti sample of durum semolina (CTRL). We ran some tests on the samples to determine breakage susceptibility by water sorption kinetics, cooking loss, the cooking resistance by fitting the values of elastic modulus, instrumental stickiness and sensory analysis. The spaghetti obtained from amaranthus flour containing CMC and PCS showed breakage susceptibility higher than that of the CTRL, while they showed a cooking resistance equal or lower with respect to the CTRL. The spaghetti with CMC had a lower stickiness, equal values of cooking loss and similar values of sensory attributes with respect to that of the CTRL. For the spaghetti containing PCS, the cooking loss values were higher and the sensorial attributes were lower with respect to that of the CTRL and of the spaghetti containing CMC. Moreover, the stickiness values for the spaghetti samples with PCS increased as the pregelatinized corn starch concentration increased. From the result it emerged that spaghetti samples containing CMC presented better performances especially in cooking with respect to the spaghetti samples with PCS.

The effect of inhomogeneous stickiness on polymer aggregation

The aggregation of polymers is important in the formation of marine aggregates and the vertical transport of material in the ocean. A polymer may be inhomogeneous along its length, with associating groups at some points along its length where bonds are more likely to form. In this paper we investigate the effects of inhomogeneous ‘stickiness’ along the polymer length. We describe the results of three-dimensional off-lattice simulations of polymer–polymer aggregation for four different types of polymer: polymers which are sticky along their entire length, polymers which are sticky at the ends only and two types of polymer which are slightly sticky along their entire length. We examine the mean radius of gyration and the fractal dimension of the resulting aggregates and the dynamics of aggregation. The slightly sticky polymers and the polymers which are sticky only at the ends form aggregates with a higher fractal dimension than the polymers which are sticky along their entire length. However, the mean radius of gyration of the aggregates formed by polymers which are sticky only at the ends is significantly larger than that of the aggregates formed from slightly sticky polymers. The aggregation dynamics are also different for the polymers which are sticky only at the ends compared to the slightly sticky polymers. A single ‘stickiness value’ is therefore likely to be inadequate to describe a polymer. We also examine the effect of polymer rigidity; it seems that the effect of inhomogeneous stickiness is greater for almost-straight polymers than for coiled chains.

ELECTROMYOGRAPHIC STUDY ON COOKED RICE WITH DIFFERENT AMYLOSE CONTENTS

ABSTRACTThe texture of six varieties of cooked rice with different amylose contents was measured with a Texturometer. Masticatory behavior of the rice was evaluated using electromyography (EMG) of masticatory muscles. Differences in mastication patterns among the seven subjects examined were greater than between rice varieties. Masticatory behavior was more related to the adhesiveness and stickiness of rice as measured using a Texturometer than to the hardness. The number of chews and masticatory time, total duration of mastication and total muscle activities were highly correlated with each other, and were greater in cooked rice with a high amylose content, which showed low adhesiveness and stickiness values using a Texturometer. Cooked rice with a high amylose content was masticated with high masseter muscle activities. The ratio of jaw‐opening muscle activity to the preceding jaw‐closing muscle activity was low in high‐amylose varieties, which corresponds to the ratio of stickiness to hardness using a Texturometer. Between‐sample differences in mastication parameters were more apparent in the early stage of mastication, and no significant diference was observed in the late stage.

PUNCTURE AND STRESS RELAXATION BEHAVIOR OF BLACKGRAM (PHASEOLUS MUNGO) FLOUR‐BASED PAPAD DOUGH

ABSTRACTPapad is a popular traditional food adjunct in South East Asian countries. The rheology of papad dough is important for the purpose of sheeting and/or rolling. In the present study, two methods for testing the behavior of papad dough (prepared from blackgram flour) have been presented and correlated with the instrumental stickiness values. These consist of an empirical method (puncture testing) and a fundamental procedure (stress relaxation characteristics). In the former method maximum stress during compression was used as an index. In the later method, the parameters determined included the stress decaying constants k1 and k2, the percent relaxation and the initial compressive stress. These tests were conducted on the papad dough with varying moisture content (32–40%) and at different dough holding (resting) times (0–120 min). Stickiness values in the range of 141 and 148° were suitable for machining of the dough to make flat circular papad sheets. The corresponding moisture content was between 35 and 36% when the holding time was in the range of 0‐30 min.

Do static electric forces contribute to the stickiness of a spider's cribellar prey capture threads?

AbstractCribellar thread is the most primitive type of prey capture thread produced by spiders. Its dry surface is formed of thousands of fine fibrils that catch on the setose surfaces of insects and, by an unknown mechanism, also hold smooth surfaces. Static electric attraction has been suggested as the force by which these smooth surfaces are held. However, when the stickiness of cribellar threads produced by Hyptiotes cavatus and Uloborus glomosus (family Uloboridae) was measured with contact plates that had similar textures but very different dielectric values, no support was found for this hypothesis. Differences in stickiness values were small and showed no relationship to the dielectric indexes of the surfaces used to measure stickiness. © 1995 Wiley‐Liss, Inc.

A method for assessing the tactile properties of dermatological cream bases

A novel technique (based on the binding capacity of cream residues, a 'bead adherence test') was developed to assess the stickiness of creams after application to the skin. A study was carried out in 24 healthy volunteers in order to relate this technique to the subjective tactile perception of four topical pharmaceutical cream bases. In comparison with Essex creme, Linola creme fett and cremor cetomacrogolis, an experimental nanoparticle water-in-oil (w/o) cream produced significantly lower stickiness values in the bead adherence test at 1 and 2 min after application. These results corresponded with the results obtained through a questionnaire dealing with the cosmetic attribute 'stickiness'. The questions concerned the cream's 'thickness', 'fattiness', 'vanishing properties' and 'appropriateness for daily use'. The nanoparticle w/o cream was preferred overall in a paired comparison preference test. In conclusion, the bead adherence test enabled the objective assessment of the stickiness of a preparation...

Eating quality indicators for waxy rices

A study of the properties of raw and cooked waxy milled rices from the Republic of Korea, the Philippines and Thailand verified that the hardness and stickiness values of cooked rices, as measured by an Instron food tester, tended to be related to final gelatinisation or birefringence end-point temperature (BEPT), neutral gel consistency or both properties of raw rices. Actual texture determination of cooked rice is required among the low final BEPT rices that have similar gel consistency and alkali test values. Intermediate final BEPT waxy rices as cooked rice had hardness and stickiness properties similar to those of high final BEPT rices.